Rodenticide compositions comprising pentaesters of tripolyphosphoric acid



Patented Sept. 19, 1950 RODENTICIDE COMPOSITIONS COMPRISING PENTAESTERS OF TRIPOLYPHOSPHORIC ACID Franklin D. Smith, Webster Groves, and John S. Harris, Richmond Heights, Mo., assignors to Monsanto Chemical Company, St. Louis, Mo., a

corporation of Delaware No Drawing. ApplicationJanuary 8, 1947, Serial No. 720,937

Claims. 1

This invention relates to new compositions of matter useful as rodenti'cides and insectivoricides, more particularly relating to contact and stomach poisons for the effective control and extermination of rodents such as rats, mice, squirrels, rabbits, gothers and prairie dogs, and insectivores such as moles.

There are many poisons and rodenticides on the market, but most all possess the undesirable and dangerous characteristic, that if not entirely consumed by the intended victim, carelessly spilled or otherwise unknowingly left unguarded, the poison remains a serious threat for extended periods to all animals or persons who might inadvertently consume or contact the toxic residue.

The object of this invention is to provide new compositions useful as rodenticides and inse-ctivoricides, a small amount, of which is definitely fatal to rodents and insectivores whether taken internally or absorbed through external contact, but possessing the desirable safety feature of hydrolyzing, by reaction with atmospheric moisture over a relatively short period, depending upon the atmospheric humidity, to form relatively non-toxic hydrolysis products.

According to the present invention, generally stated, we have discovered that certai pentaesters of tripolyphosphoric acid, illustrated by the empirical formula R5P30l0 wherein R is a radical containing 1 to 4 carbon atoms selected from the group consisting of alkyl, haloalkyl, alkenyl, or cycloalkyl, are highly desirable as the toxic agents in rodenticide and insectivoricide compositions. We prefer to use the pentaethyl ester of tripolyphosphoric acid in our rodenticide and inse-ctivoricide compositions. For example, it has been found that the lethal dose of pentaethyl tripolyphosphate for rats is 5 milligrams per kilogram of the rodents body weight, when given orally to the rats in the form of a 2% aqueous solution. In a similar manner, 4.5 milligrams of pentaethyl tripolyphosphate per kilogram .body Weight, when orally administered as a 1% aqueous solution, isfatal to rats.

When cutaneously applied to rabbits, the lethal dose in all dilutions is approximately '75 milligrams of the pentaethyl tripolyphosphate per kilogram of body Weight.

I It takes several days of prolonged contactwith moisture for the hydrolysis of the 'toxicant in the composition of the present invention to be complete. This allows sufficient time to poison the rodent or insectivore, but insures that any unconsumed poison will not be available at a later 2, time to inadvertently poison other animals. This hydrolysis reaction may be retarded by combining the toxic material with oils, a process to be fully described in later paragraphs.

While we preferably use the pentaethyl ester of tripolyphosphoric acid in my compositions, the pentaethyl,v pentapropyl, pentabuty1 and their halogen substitution products exhibit marked toxicity toward rodents and insectivores. In a similar manner the pentaalkenyl esters of tripolyphosphoric acid, such as the pentaacrylyl ester are effective as rodenticides. Likewise, pentacyclopropyl and pentacyclobutyl esters may be used as the lethal agent in the compositions; While we have found that baits or compositions containing 0.3 of 1% to 20% of pentaesters of tripolyphosphoric acid are effective as rodenticides and insectivoricides, and concentrations of to 1% to 10% are equally useful, we prefer concentrations of /2 of 1% to 5% as the range efiective for niost all rodents and insectivores encountered.

The pentaesters of tripolyphosphoric acid may be prepared in the manner illustrated by the preparation of pentaethyltripolyphosphate: '7 moles of triethylorthophosphate is heated to 1501 C., with stirring and refluxing, and slowly in a dropwise manner 2 moles of phosphorus oxychloride is added. The esterification is completed by refluxing at'a temperature below (3.7 for 30 minutes after all the phosphorus oxychlo ride has been added. The reaction product is substantially the pentaethyl ester of tripolyphosphoric acid and may be used as the toxic .ingredient of my composition without further treatment. These pentaesters of tripolyphosphoric acid may also be prepared in the manner illustrated by the preparation of the pentamethyl ester of tripolyphosphoric acid: '71 grams of P205 is slowly and with stirring added to grams of trimethylorthophosphate, mole ratio of 2 moles of P205 to- 5 moles trimethylorthophosphate, in a' water cooled reaction vessel, wherein the reaction temperature is maintained at 50 C., and

the stirring continued until all the the P205 has reacted. The reaction product is substantially the pentamethyl tripolyphosphate and may be used as the toxic ingredient of the rodenticide compositions of this invention without further treatment. I

The compositions of this invention may be prepared for effective presentation to the rodent in various ways. For example, the pentaester may be mixed with a carrier as edible oils, such as cottonseed oil, soybean oil, corn oil, fish oil, tallow,

lard or drippings, or light oils such as mineral oil, and used as such or combined with a food or cereal product such as bread, flour, oatmeal, bran, barley flour or cornmeal, or other meals such as alfalfa or. clover meal. The composition with cereals may be used in the meal form or the meal may be pelleted or briquetted for ease in han. dling, placing, and distribution. As an alternative, the meal may be pelleted and thereafter im pregnated With the pentaester or an oil solution thereof.

The preferred method is to prepare an oil con centrate wherein the pentaester of tripolypho-sphoric acid selected for the rodenticide or insectivoricide is mixed with one of the above described oils. A bait is then prepared comprising the concentrate which is mixed with or poured over one aqueous compositions are desirably used as soon as possible after preparation.

L Example IV aniseed oil to mask the odor of the ester. This oil 7 phosphate ester.

of the cereal or food products and allowed to soak or steep until all of the oil concentrate is absorbed. A toxic bait which will be effective for several days may be prepared by mixing Water and one of the toxic pentaesters of tripolyphose phoricacid and soaking or steeping bread, cereal meal or cereal pellets in the aqueous solution. Also, a toxic oil composition may be prepared and used as'an oil rodenticide by mixing 0.5% to of .apentaester of tripolyphosphoric acid with one'of the above described oils. Other toxicants may'be'incorporated in the composition if desired, although the compositions are outstandingly effective without such additional toxicants.

The pentaesters possess sucha high toxicity that it is undesirable to attempt to use them as rodenticides or insectivoricides in high concentrations or without the aid of a carrier or diluent. Also at the higher concentrations, the slight odor of the pentaesters becomes more diificult to mask, and the rodents will be repelled rather than attracted to the bait.

The following examples are for the purpose of illustrating the utility and methods of preparing toxic baits for presentation to rodents and insectivores, but it is not intended that the scope of the invention be limited by the examples.

7 Example I An effective rodenticide and insectivoricide' composition may be prepared by mixing together 98.7 grams'of corn oil and11.4 grams (1 ml.) of the pentaethyl ester of tripolyphosphoric acid with suflicient aniseed oil to give the composition a faint odor attractive to. rodents. While-this com- I position-is a concentrate and is intended to be Example II The 100 grams of concentrate prepared-in Example I is poured over 100 grams of pelleted cereal meal and mixed until all of the oil is taken up by the pellets. The poisoned bait is then placed where it may be conveniently eaten by the'rodent .or in-' sectivore.

20.0 ml. of pentachlorethyltripolyphosphate. is mixed with 98.7 ml. of water to whichisadd ed sufficient aniseed oil to mask the faint odor of the phosphate ester. This aqueous-mixture isadded to 100 grams of cornmeal and mixed well. The

- ExampZe' III I and moles.

is then poured over 200 grams of chopped or ground bacon rind, cracklings, or ground meat and mixed well. This is an effective bait for rats Example V 10 ml. of pentabutyltripolyphosphate is mixed with grams of cottonseed oil to which is added suflicient aniseed oil to mask the faint odor of the This toxic mixture is then poured over 300 grams of alfalfa meal and mixed until all of the oil is absorbed by the meal. The

meal may then be pelleted or briquetted to form an eifective bait for rats and moles.

Example VI 5 ml. of pentamethyltripolyphosphate is mixed into grams of lard. Sufiicient aniseed oil is added to mask the odor of the ester, and the toxic mixture is then spread on to 400 grams of bread.

- Example VII 20 of a pentaester of tripolyphosphoric acid, the, said ester residue being a radical containing from 1 to 4 carbon atoms selected fromthe group consisting of alkyl, chloralkyl, alkenyl and cycloalkyl. 2. A rodenticide composition comprising a processed solid food product and 0.5 to 2 0% of pentaethyl tripolyphosphate.

3.'A rodenticide composition comprising a cereal product and 0.5 .to' 5% of pentaethyl tripolyphosphate.

4. A rodenticide composition comprising a processed solid food product, an edible oil and 05 to 5% of pentaethyl tripolyphosphate.

5. A rodenticide composition comprising a processed solid food product and 0.5 to 20% of penta (chloralkyl) tripolyphosphate.

- FRANKLIN D. SMITH.

J GEN S. HARRIS.

REFERENCES orrED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,224,695 Prutton Dec. 10, 1940 FOREIGN PATENTS Number .Country Date 333,216 Great Britain Aug. .6, 1930 r OTHER REFERENCES "B. 1.0. S.Final Report No. 1095, published in LondomMarch 24, 1947, pages 21, 22.

Chem. and E g JNQ WS, September pages 1520-1521.

Adler et al., Chemical Industries, v01. 51, October 1942, page 516. 

1. A RODENTICIDE AND INSECTIVORICIDE COMPOSITION COMPRISING A PROCESSED SOLID FOOD PRODUCT AS AN EDIBLE CARRIER AND AS A TOXIC INGREDIENT, 0.5 TO 20% OF A PENTAESTER OF TRIPOLYPHOSPHORIC ACID, THE SAID ESTER RESIDUE BEING A RADICAL CONTAINING FROM 1 TO 4 CARTON ATOMS SELECTED FROM THE GROUP CONSISTING OF ALKYL, CHLORALKYL, ALKENYL AND CYCLOALKYL. 